/* 
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System;

namespace Lucene.Net.Index
{
    
    sealed class IntBlockPool
    {
        private void  InitBlock()
        {
            intUpto = DocumentsWriter.INT_BLOCK_SIZE;
        }
        
        public int[][] buffers = new int[10][];
        
        internal int bufferUpto = - 1; // Which buffer we are upto
        public int intUpto; // Where we are in head buffer
        
        public int[] buffer; // Current head buffer
        public int intOffset = - DocumentsWriter.INT_BLOCK_SIZE; // Current head offset
        
        private DocumentsWriter docWriter;
        internal bool trackAllocations;
        
        public IntBlockPool(DocumentsWriter docWriter, bool trackAllocations)
        {
            InitBlock();
            this.docWriter = docWriter;
            this.trackAllocations = trackAllocations;
        }
        
        public void  Reset()
        {
            if (bufferUpto != - 1)
            {
                if (bufferUpto > 0)
                // Recycle all but the first buffer
                    docWriter.RecycleIntBlocks(buffers, 1, 1 + bufferUpto);
                
                // Reuse first buffer
                bufferUpto = 0;
                intUpto = 0;
                intOffset = 0;
                buffer = buffers[0];
            }
        }
        
        public void  NextBuffer()
        {
            if (1 + bufferUpto == buffers.Length)
            {
                int[][] newBuffers = new int[(int) (buffers.Length * 1.5)][];
                Array.Copy(buffers, 0, newBuffers, 0, buffers.Length);
                buffers = newBuffers;
            }
            buffer = buffers[1 + bufferUpto] = docWriter.GetIntBlock(trackAllocations);
            bufferUpto++;
            
            intUpto = 0;
            intOffset += DocumentsWriter.INT_BLOCK_SIZE;
        }
    }
}